Implement a new type trait __is_trivially_constructible(T, Args...)

that provides the behavior of the C++11 library trait
std::is_trivially_constructible<T, Args...>, which can't be
implemented purely as a library.

Since __is_trivially_constructible can have zero or more arguments, I
needed to add Yet Another Type Trait Expression Class, this one
handling arbitrary arguments. The next step will be to migrate
UnaryTypeTrait and BinaryTypeTrait over to this new, more general
TypeTrait class.

Fixes the Clang side of <rdar://problem/10895483> / PR12038.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151352 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 80 insertions, 1 deletions

diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index a1770c915a..37df90407d 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -2169,6 +2169,7 @@ Expr::CanThrowResult Expr::CanThrow(ASTContext &C) const {
   case AddrLabelExprClass:
   case ArrayTypeTraitExprClass:
   case BinaryTypeTraitExprClass:
+  case TypeTraitExprClass:
   case CXXBoolLiteralExprClass:
   case CXXNoexceptExprClass:
   case CXXNullPtrLiteralExprClass:
diff --git a/lib/AST/ExprCXX.cpp b/lib/AST/ExprCXX.cpp
index 7ef3417e6d..da89bf2798 100644
--- a/lib/AST/ExprCXX.cpp
+++ b/lib/AST/ExprCXX.cpp
@@ -199,7 +199,6 @@ SourceRange CXXPseudoDestructorExpr::getSourceRange() const {
   return SourceRange(Base->getLocStart(), End);
 }
 
-
 // UnresolvedLookupExpr
 UnresolvedLookupExpr *
 UnresolvedLookupExpr::Create(ASTContext &C, 
@@ -1262,4 +1261,51 @@ TemplateArgument SubstNonTypeTemplateParmPackExpr::getArgumentPack() const {
   return TemplateArgument(Arguments, NumArguments);
 }
 
+TypeTraitExpr::TypeTraitExpr(QualType T, SourceLocation Loc, TypeTrait Kind,
+                             ArrayRef<TypeSourceInfo *> Args,
+                             SourceLocation RParenLoc,
+                             bool Value)
+  : Expr(TypeTraitExprClass, T, VK_RValue, OK_Ordinary,
+         /*TypeDependent=*/false,
+         /*ValueDependent=*/false,
+         /*InstantiationDependent=*/false,
+         /*ContainsUnexpandedParameterPack=*/false),
+    Loc(Loc), RParenLoc(RParenLoc)
+{
+  TypeTraitExprBits.Kind = Kind;
+  TypeTraitExprBits.Value = Value;
+  TypeTraitExprBits.NumArgs = Args.size();
+
+  TypeSourceInfo **ToArgs = getTypeSourceInfos();
+  
+  for (unsigned I = 0, N = Args.size(); I != N; ++I) {
+    if (Args[I]->getType()->isDependentType())
+      setValueDependent(true);
+    if (Args[I]->getType()->isInstantiationDependentType())
+      setInstantiationDependent(true);
+    if (Args[I]->getType()->containsUnexpandedParameterPack())
+      setContainsUnexpandedParameterPack(true);
+    
+    ToArgs[I] = Args[I];
+  }
+}
+
+TypeTraitExpr *TypeTraitExpr::Create(ASTContext &C, QualType T, 
+                                     SourceLocation Loc, 
+                                     TypeTrait Kind,
+                                     ArrayRef<TypeSourceInfo *> Args,
+                                     SourceLocation RParenLoc,
+                                     bool Value) {
+  unsigned Size = sizeof(TypeTraitExpr) + sizeof(TypeSourceInfo*) * Args.size();
+  void *Mem = C.Allocate(Size);
+  return new (Mem) TypeTraitExpr(T, Loc, Kind, Args, RParenLoc, Value);
+}
+
+TypeTraitExpr *TypeTraitExpr::CreateDeserialized(ASTContext &C,
+                                                 unsigned NumArgs) {
+  unsigned Size = sizeof(TypeTraitExpr) + sizeof(TypeSourceInfo*) * NumArgs;
+  void *Mem = C.Allocate(Size);
+  return new (Mem) TypeTraitExpr(EmptyShell());
+}
+
 void ArrayTypeTraitExpr::anchor() { }
diff --git a/lib/AST/ExprClassification.cpp b/lib/AST/ExprClassification.cpp
index 79d8dc48fe..1b04428fae 100644
--- a/lib/AST/ExprClassification.cpp
+++ b/lib/AST/ExprClassification.cpp
@@ -151,6 +151,7 @@ static Cl::Kinds ClassifyInternal(ASTContext &Ctx, const Expr *E) {
   case Expr::CXXScalarValueInitExprClass:
   case Expr::UnaryTypeTraitExprClass:
   case Expr::BinaryTypeTraitExprClass:
+  case Expr::TypeTraitExprClass:
   case Expr::ArrayTypeTraitExprClass:
   case Expr::ExpressionTraitExprClass:
   case Expr::ObjCSelectorExprClass:
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index ed64153f85..85aa5ee81e 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -4119,6 +4119,10 @@ public:
     return Success(E->getValue(), E);
   }
 
+  bool VisitTypeTraitExpr(const TypeTraitExpr *E) {
+    return Success(E->getValue(), E);
+  }
+
   bool VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) {
     return Success(E->getValue(), E);
   }
@@ -6360,6 +6364,7 @@ static ICEDiag CheckICE(const Expr* E, ASTContext &Ctx) {
   case Expr::CXXScalarValueInitExprClass:
   case Expr::UnaryTypeTraitExprClass:
   case Expr::BinaryTypeTraitExprClass:
+  case Expr::TypeTraitExprClass:
   case Expr::ArrayTypeTraitExprClass:
   case Expr::ExpressionTraitExprClass:
   case Expr::CXXNoexceptExprClass:
diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp
index 5e167f58dc..91e6ee5c97 100644
--- a/lib/AST/ItaniumMangle.cpp
+++ b/lib/AST/ItaniumMangle.cpp
@@ -2383,6 +2383,7 @@ recurse:
   case Expr::StmtExprClass:
   case Expr::UnaryTypeTraitExprClass:
   case Expr::BinaryTypeTraitExprClass:
+  case Expr::TypeTraitExprClass:
   case Expr::ArrayTypeTraitExprClass:
   case Expr::ExpressionTraitExprClass:
   case Expr::VAArgExprClass:
diff --git a/lib/AST/StmtPrinter.cpp b/lib/AST/StmtPrinter.cpp
index 51296ad5f4..6d3e783f22 100644
--- a/lib/AST/StmtPrinter.cpp
+++ b/lib/AST/StmtPrinter.cpp
@@ -1555,6 +1555,13 @@ static const char *getTypeTraitName(BinaryTypeTrait BTT) {
   llvm_unreachable("Binary type trait not covered by switch");
 }
 
+static const char *getTypeTraitName(TypeTrait TT) {
+  switch (TT) {
+  case clang::TT_IsTriviallyConstructible:return "__is_trivially_constructible";
+  }
+  llvm_unreachable("Type trait not covered by switch");
+}
+
 static const char *getTypeTraitName(ArrayTypeTrait ATT) {
   switch (ATT) {
   case ATT_ArrayRank:        return "__array_rank";
@@ -1582,6 +1589,16 @@ void StmtPrinter::VisitBinaryTypeTraitExpr(BinaryTypeTraitExpr *E) {
      << E->getRhsType().getAsString(Policy) << ")";
 }
 
+void StmtPrinter::VisitTypeTraitExpr(TypeTraitExpr *E) {
+  OS << getTypeTraitName(E->getTrait()) << "(";
+  for (unsigned I = 0, N = E->getNumArgs(); I != N; ++I) {
+    if (I > 0)
+      OS << ", ";
+    OS << E->getArg(I)->getType().getAsString(Policy);
+  }
+  OS << ")";
+}
+
 void StmtPrinter::VisitArrayTypeTraitExpr(ArrayTypeTraitExpr *E) {
   OS << getTypeTraitName(E->getTrait()) << "("
      << E->getQueriedType().getAsString(Policy) << ")";
diff --git a/lib/AST/StmtProfile.cpp b/lib/AST/StmtProfile.cpp
index fdd0c8502d..643bca817c 100644
--- a/lib/AST/StmtProfile.cpp
+++ b/lib/AST/StmtProfile.cpp
@@ -868,6 +868,14 @@ void StmtProfiler::VisitBinaryTypeTraitExpr(const BinaryTypeTraitExpr *S) {
   VisitType(S->getRhsType());
 }
 
+void StmtProfiler::VisitTypeTraitExpr(const TypeTraitExpr *S) {
+  VisitExpr(S);
+  ID.AddInteger(S->getTrait());
+  ID.AddInteger(S->getNumArgs());
+  for (unsigned I = 0, N = S->getNumArgs(); I != N; ++I)
+    VisitType(S->getArg(I)->getType());
+}
+
 void StmtProfiler::VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *S) {
   VisitExpr(S);
   ID.AddInteger(S->getTrait());